If you are using native C, C++ etc the host by DMMD would be a better fit, and it is probably more compatible with newer plugins as it implements the PICA suites.

First, awesome idea from your part, and I wish you good luck with it.

Second, thanks @null54 for promote our Photoshop Host SDK http://www.thepluginsite.com/forum/viewtopic.php?f=15&t=3992. Indeed it contain only one ANS C dll which can be called from multiple language programming. Unfortunately we didn't have time for creating Mac version as I promised, but I hope we'll find time in one day.